A 2200-year record of Andean Condor diet and nest site usage reflects natural and anthropogenic stressors

Understanding how animals respond to large-scale environmental changes is difficult to achieve because monitoring data are rarely available for more than the past few decades, if at all. Here, we demonstrate how a variety of palaeoecological proxies (e.g. isotopes, geochemistry and DNA) from an Andean Condor (Vultur gryphus) guano deposit from Argentina can be used to explore breeding site fidelity and the impacts of environmental changes on avian behaviour. We found that condors used the nesting site since at least approximately 2200 years ago, with an approximately 1000-year nesting frequency slowdown from ca 1650 to 650 years before the present (yr BP). We provide evidence that the nesting slowdown coincided with a period of increased volcanic activity in the nearby Southern Volcanic Zone, which resulted in decreased availability of carrion and deterred scavenging birds. After returning to the nest site ca 650 yr BP, condor diet shifted from the carrion of native species and beached marine animals to the carrion of livestock (e.g. sheep and cattle) and exotic herbivores (e.g. red deer and European hare) introduced by European settlers. Currently, Andean Condors have elevated lead concentrations in their guano compared to the past, which is associated with human persecution linked to the shift in diet.Fil: Duda, Matthew P.. Queen's University; CanadáFil: Grooms, Christopher. Queen's University; CanadáFil: Sympson, Lorenzo. Sociedad Naturalista Andino Patagonica; ArgentinaFil: Blais, Jules M.. University of Ottawa; CanadáFil: Dagodzo, Daniel. University of Ottawa; CanadáFil: Feng, Wenxi. Queen's University; CanadáFil: Hayward, Kristen M.. Queen's University; CanadáFil: Julius, Matthew L.. St. Cloud State University; Estados UnidosFil: Kimpe, Linda E.. University of Ottawa; CanadáFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Layton Matthews, Daniel. Queen's University; CanadáFil: Lougheed, Stephen. Queen's University; CanadáFil: Massaferro, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Michelutti, Neal. Queen's University; CanadáFil: Pufahl, Peir K.. Queen's University; CanadáFil: Vuletich, April. Queen's University; CanadáFil: Smol, John P.. Queen's University; Canad

Fiction Fix 10

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The Cost of Sex: Quantifying Energetic Investment in Gamete Production by Males and Females

The relative energetic investment in reproduction between the sexes forms the basis of sexual selection and life history theories in evolutionary biology. It is often assumed that males invest considerably less in gametes than females, but quantifying the energetic cost of gamete production in both sexes has remained a difficult challenge. For a broad diversity of species (invertebrates, reptiles, amphibians, fishes, birds, and mammals), we compared the cost of gamete production between the sexes in terms of the investment in gonad tissue and the rate of gamete biomass production. Investment in gonad biomass was nearly proportional to body mass in both sexes, but gamete biomass production rate was approximately two to four orders of magnitude higher in females. In both males and females, gamete biomass production rate increased with organism mass as a power law, much like individual metabolic rate. This suggests that whole-organism energetics may act as a primary constraint on gamete production among species. Residual variation in sperm production rate was positively correlated with relative testes size. Together, these results suggest that understanding the heterogeneity in rates of gamete production among species requires joint consideration of the effects of gonad mass and metabolism

Empowering older adults living in long-term care homes: Breaking the silence around death and dying

This qualitative study draws on resident focus group data from Phase I of a larger study entitled "Strengthening a Palliative Approach to Care." Twenty-two long-term care (LTC) residents from four LTC homes in southern Ontario participated in semi-structured focus groups. The study aimed to (1) examine how older adults living in LTC understand and experience palliative care; (2) explore how current understandings and experiences of palliative care can be adapted to address the needs of LTC residents; (3) propose practice recommendations for addressing the needs of this population; and (4) add to the existing conceptual and theoretical frameworks for a palliative approach to care. The findings revealed that a culture of silence was present when it came to death and dying, reinforced by residents' pre-existing disempowerment, limited staff initiative, lack of acknowledgment and support when residents witnessed others dying, and an exclusive focus on medical advance directives. Importantly, the findings showed that it was possible to challenge this culture of silence by showing interest, taking initiative, providing information, taking time, and being sensitive to residents' needs and experiences. During these focus groups, residents expressed clear wishes for their own end-of-life. Policy and practice implications include the need for practices that support people's initial transition and adaptation to LTC, tools that support a culture of open communication around death and dying and that place residents at the centre of their care, and broadening palliative care policy to extend beyond only end-of-life.Cette étude qualitative fait appel à des données récoltées lors de l'étape 1 d'une étude plus vaste qui s'intitule : « Strengthening a Palliative Approach to Care ». Pendant cette étude, 22 personnes hébergées dans quatre centres de soins de longue durée (SLD) du sud de l'Ontario ont participé à des groupes de concertation semi-structurés. L'étude consistait à (1) examiner le niveau de compréhension et l'expérience des personnes âgées habitant en SLD et admis en soins palliatifs ; (2) étudier comment la compréhension et l'expérience actuelles des soins palliatifs pourraient être adaptées afin de mieux répondre aux besoins de résidents en SLD ; (3) présenter des recommandations sur les pratiques à appliquer pour mieux répondre aux besoins des résidents ; et (4) bonifier les cadres conceptuel et théorique existants d'une approche palliative envers les soins. Les conclusions de l'étude ont révélé qu'une culture du silence entoure la mort et le mourir et qu'elle est renforcée par la déresponsabilisation préexistante des résidents, l'initiative limitée du personnel, le manque de reconnaissance et de soutien envers les résidents qui ont été en présence d'une personne mourante, et l'importance accordée uniquement aux directives médicales préalables. Il est à noter que les conclusions ont également démontré qu'il était possible de défier cette culture en montrant un intérêt, en saisissant l'initiative, en fournissant de l'information, en prenant le temps, et en restant sensible aux besoins et aux expériences des résidents. Lors des groupes de concertation, les résidents ont exprimé des souhaits clairs pour leur propre fin de vie. Les conséquences de l'étude sur les politiques et les pratiques comprennent le besoin d'agir pour appuyer les personnes âgées lors de leur transition initiale vers les SLD et leur adaptation à ce milieu, des outils qui promeuvent une culture de communication ouverte autour de la mort et du mourir et qui situent les résidents au cœur de leurs propres soins, ainsi que l'élargissement de la politique des soins palliatifs afin qu'elle s'étende au-delà de la fin de vie

Explaining Differences in the Lifespan and Replicative Capacity of Cells: A General Model and Comparative Analysis of Vertebrates

A better understanding of the factors that govern individual cell lifespan and the replicative capacity of cells (i.e. Hayflick\u27s limit) is important for addressing disease progression and ageing. Estimates of cell lifespan in vivo and the replicative capacity of cell lines in culture vary substantially both within and across species, but the underlying reasons for this variability remain unclear. Here, we address this issue by presenting a quantitative model of cell lifespan and cell replicative capacity. The model is based on the relationship between cell mortality and metabolic rate, which is supported with data for different cell types from ectotherms and endotherms. These data indicate that much of the observed variation in cell lifespan and cell replicative capacity is explained by differences in cellular metabolic rate, and thus by the three primary factors that control metabolic rate: organism size, organism temperature and cell size. Individual cell lifespan increases as a power law with both body mass and cell mass, and decreases exponentially with increasing temperature. The replicative capacity of cells also increases with body mass, but is independent of temperature. These results provide a point of departure for future comparative studies of cell lifespan and replicative capacity in the laboratory and in the field

Common metabolic constraints on dive duration in endothermic and ectothermic vertebrates

Dive duration in air-breathing vertebrates is thought to be constrained by the volume of oxygen stored in the body and the rate at which it is consumed (i.e., “oxygen store/usage hypothesis”). The body mass-dependence of dive duration among endothermic vertebrates is largely supportive of this model, but previous analyses of ectothermic vertebrates show no such body mass-dependence. Here we show that dive duration in both endotherms and ectotherms largely support the oxygen store/usage hypothesis after accounting for the well-established effects of temperature on oxygen consumption rates. Analyses of the body mass and temperature dependence of dive duration in 181 species of endothermic vertebrates and 29 species of ectothermic vertebrates show that dive duration increases as a power law with body mass, and decreases exponentially with increasing temperature. Thus, in the case of ectothermic vertebrates, changes in environmental temperature will likely impact the foraging ecology of divers